What oil pressure may cause both amber and red OIL PX annunciators to illuminate at idle power?

The illumination of both the amber and red OIL PX annunciators at idle power is a critical indicator of engine oil pressure. When the oil pressure falls between 15 psi and 40 psi, it signifies a potentially deteriorating condition of the oil system that may lead to engine performance issues or even failure if not addressed.

The amber annunciator typically signifies a cautionary level, indicating that the oil pressure has fallen into a lower-than-normal range but may not be immediately critical, while the red annunciator serves as an alert for a condition that requires immediate attention, indicating that the oil pressure is dangerously low and could lead to serious engine damage. Therefore, when oil pressure readings are between 15 psi and 40 psi, it is normal to see both the amber and red lights activated, prompting the need for immediate monitoring and action to ensure the engine's safety and performance.

Other pressure ranges do not accurately reflect the thresholds at which these warnings would be triggered, making this the correct choice for the question about oil pressure and its impact on the annunciators.